I bet you wouldn't even think of insulting your wedding guests! After all they are coming to your wedding, bringing a gift and giving you good wishes. You wouldn't even dream of it. They are perhaps relatives and good friends and you would rather die than insult and yet people do!
Looking for their wedding stationery they go to Ebay because they are cheaper there and they think sure who will know the price. They scroll down through hundreds of invites listed and think they will cut costs in going for something cheap. Invites selling at 50 for £35 working out at 70p each! never thinking what quality they are. Well, be sure your guests will! How many times have we seen handmade cards so much like homemade, cheap, nasty, insulting and tacky. Peel offs because they have no hot foiler or stick ons that fall off in the post.
If your guest was to give you a gift in the same vein as you think. Imagine what it would be like. "I saw this wee item in the Poundstore and I'm sure the bride and groom would be able to make use of that. Cheap and cheerful but sure they will never know where I got it. Now, rather than use paper that they will tear off at £1 a sheet, I have some used left over paper. I'll smooth it out and wrap the present and they will never know."
What would you say? You would be appalled and yet so many are doing it sending those awful invitations. You set the standard by sending them in the first place. Think about it. There are lots of quality invitations on Ebay but forget about those cheap and nastys. Maybe then the so called designers will realise quantity doesn't sell but quality.
Treat your guests with respect and they will surprise you!